RAN: Redesigning the American Neighborhood Project

RAN pollutants

Stormwater Basics: Pollutants

The Vermont Stormwater Manual, (vol. 1 and vol. 2) is a valuable resource for background data and approaches for stormwater management as it pertains specifically to Vermont. Below are pollutant averages (vol. 2; p. 15) which we might expect to see in stormwater:

While these amounts may not seem significant, consider how 55 mg/L TSS would add up:

In peak storm events, we have measured 5000 liters/second flowing through Tributary 7 of Potash Brook. At this rate, there would be 275,000 mg TSS/second, or 275 grams TSS/second, or 0.6 pounds TSS/second! Were this amount sustained, it would translate into 36 pounds per minute of sediment flowing through the tributary!